Hi Pavithra, I forgot to mention that you could just go to the UniProt web site and save the sequence as a file, then open the file in Chimera. For example, I went to UniProt, searched for oprd_human, then in the Sequences section of the oprd_human page, clicked "FASTA" to get to the URL below, contents of which you can save as plain text file named ending in .fa or .fasta and then open in Chimera with File... Open. <http://www.uniprot.org/uniprot/P41143.fasta> It would not have the annotations mentioned in the comparative modeling tutorial, but those aren't important for doing the tutorial. After opening the FAST file as described above, you can then carry on with the tutorial starting with the fourth paragraph in the "Blast Search for Templates" section ("The next step...". <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/tutorials/dor.html> Best, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco